Biochemisch-technologische Studienüber die Naßverarbeitung von Mais 4. Mitteilung. Über die qualitative Zusammensetzung des Mais-Hydrolasensystems und Aktivität einzelner Enzyme bzw. Enzymgruppen

Biochemical-technological Studies on Wet-Processing of Maize. Part 4. On the Qualitative Composition of the Maize Hydrolase System and the Activity of Particular Enzymes Respectively Enzyme Groups. Enzyme preparations have been isolated from the maize meal by means of water extraction and following protein precipitation (ethanol, ammonium sulphate, acetone). Cleaning or concentration operations have been left out, in order to preserve the enzyme system of the maize in its totality By paper chromatographical studies on these preparations as well as special activity deter minations a- and β- amylase could be traced in the ungerminated as well as in the germinated maize and the presence of phosphorylase could be confirmed. For enzymatic handling of the non-gelatinized starch a- amylase is above all convenient, but slight degradation by β-amylase cannot be overlooked. By means of paper chromatography and reductometry β-fructofuranosidase, a-glucosidase, β-glucosidase could be clearly traced in the germinated and ungerminated maize. a-Galactosidase could be traced with some reservation. Matters in this group have in common the faculty for hydrolysis and synthesis of glucosidic bondings. Proteinase and lipase have been traced in all preparations, peptidase exclusively in those from germinated maize and their activities have been determined. Of all the maize sorts examined, hard maize shows higher activities with all enzyme species compared to dent maize.     

Polystyrolgebundene Glucoamylase: Kinetisches Verhalten des Enzyms aus Endomycopsis bispora gegenüber technischen Substratlösungen

Polystyrene-bound Glucoamylase: Kinetic Behaviour of the Enzyme from Endomycopsis bispora Towards Technical Substrates. Glucoamylase from Endomycopsis bispora was covalently bound by glutaraldehyde to macroporous poly(ethylenediaminomethyl styrene). The kinetics of this enzyme derivative towards acid-liquified maize starch (DE = 20,8%; DX = 4,5%) were studied in the batch and column reactor. In addition, the reactor dimension and the amount of immobilized enzyme were varied. Several parameters affecting the heterogeneous enzyme reaction were discussed using experimental and calculated data. Due to the high specific and relative activity and the favourable mechanical and hydrodynamic properties of the support, polystyrene-glucoamylase is interesting for the technical starch hydrolysis.     

Electron Backscatter Diffraction (EBSD) Study of the Structure and Crystallography of the Barnacle Balanus amphitrite

This work presents novel mapping of the structure and crystallography of the shell of the barnacle Balanus amphitrite. Calcium carbonate in the form of hexagonal calcite was observed, with fine crystallites on the order of 1 μm in diameter forming clusters of similar orientation. While no apparent preferred orientation was measured in the parietal shell cross section, the base plate shell cross section revealed a preference for the alignment of the 〈0001〉 direction at the exterior of the shell, rotating by 90° toward the center of the base plate cross-section. These maps will be used to construct image-based models of the barnacle shell for further study of mechanical response.     

T cell rescue of monocytes from apoptosis: role of the CD40-CD40L interaction and requirement for CD40-mediated induction of protein tyrosine kinase activity

Circulating monocytes have a limited life span and will undergo apoptosis in the absence of specific stimuli. Recent studies have demonstrated that monocytes can be rescued from apoptosis via lipopolysaccharide (LPS) activation or stimulation with interleukin-1 or tumor necrosis factor-alpha. Based on previous studies from our laboratory, we hypothesized that, in nonseptic (e.g., autoimmune) inflammation, the presence of activated T cells may enhance monocyte longevity through T cell contact-dependent signaling. Plasma membranes prepared from 6 h activated (TmA) and resting (TmR) purified CD4+ T cells were added to resting elutriation-purified monocytes cultured in serum-free medium. Cells were assayed for degree of apoptosis occurring over a 72-h incubation using both agarose gel electrophoresis and flow cytometry. The addition of TmA (but not TmR) was capable of blocking monocyte apoptosis and the ability of TmA to rescue monocytes was abrogated by the addition of anti-CD40L antibodies. Rescue of monocytes from apoptosis could also be mediated by direct cross-linking of monocyte CD40. Inhibitors of tyrosine kinase activity blocked both TmA and anti-CD40-mediated rescue of monocytes from apoptosis, suggesting a primary role of a tyrosine kinase signaling pathway in the events controlling monocyte longevity.     

Plasma and lipoprotein lipid responses to four hypolipid drugs

The responses of 14 hyperlipidemic subjects to 4 hypolipidemic agents were compared by measureing cholesterol and triglyceride in whole plasma, very low density lipoproteins (VLDL), low density lipoproteins (LDL), and high density lipoproteins (HDL) monthly for 2 months before and 3 months during treatment with each of 4 drugs: clofibrate, 2 g/d; colestipol, 20 g/d; para-aminosalicylic acid-ascorbate (PAS-C), 6–8 g/d; and oxandrolone, 7.5 mg/d. Lipid responses proved to be stable by the first monthly evaluation both off and on each drug. Mean adherence was high and similar for all agents (81–92% of the prescribed dose). Clofibrate was associated with significant decreases in mean plasma cholesterol (−16%, p<.01), plasma triglyceride (−51%, p<.005), VLDL-cholesterol (−61%, p<.005) and VLDL-triglyceride (−61%, P<.005), while HDL cholesterol increased (+20%, p<.01), and the LDL-cholesterol/HDL ratio declined (−24%, p<.05). Colestipol was associated with decreases in mean plasma cholesterol (−15%, p<.01) and LDL-cholesterol (−22%, p<.05), while VLDL-triglyceride increased (+41%, p<.05), and the LDL-cholesterol/HDL-cholesterol ratio declined (−25%, p<.05). PAS-C was associated with decreases in VLDL-cholesterol (−30%, p<.05), and VLDL-triglyceride (−29%, p<.05), while the LDL-cholesterol/HDL-cholesterol ratio remained unchanged. Oxandrolone was associated with increases in mean plasma cholesterol (+7%, p<.05), LDL-cholesterol (+45%, p<.005 [+25% excluding one subject who increased 298%]), and LDL-triglyceride (+24%, p<.01), while decreases occurred in plasma triglyceride (−31%, p<.05), VLDL-cholesterol (−26%, p<.05), VLDL-triglyceride (−42%, p<.005), HDL-cholesterol (−45%, p<.005), and HDL-triglyceride (−43%, p<.01). The mean LDL-cholesterol/HDL-cholesterol ratio increased by 109% (p<.005), reflecting the reciprocal changes in LDL and HDL. Thus, while both clofibrate and colestipol were associated with significant, equivalent reductions in theoretical atherogenic risk, oxandrolone produced a net effect that was not only adverse but 4 times that magnitude, suggesting caution in its long-term use, even for the management of hypertriglyceridemia. William R. Hazzard was an investigator of the Howard Hughes Medical Institute during the course of this study Claude Gagne was a research fellow of the Medical Research Council of Canada during the course of this study. John J. Albers is an established investigator of the American Heart Association. of this study     

Functional properties of glycine receptors expressed in primary cultures of mouse cerebellar granule cells

Expression of the glycine receptor was investigated in membranes prepared from primary cultures of mouse cerebellar granule cells and postnatal mouse cerebellum using the antagonist [3H]strychnine for ligand binding. Scatchard analysis of the binding data obtained from P17 cerebellum showed a single population of binding sites (K(D) approximately 6 nM) and [3H]strychnine binding to membranes prepared from cultured neurons and P17 cerebellum was found to have the same sensitivity to the glycinergic agonists glycine, beta-alanine and taurine. The development of [3H]strychnine binding sites in cultured cerebellar granule cells and cerebellum showed opposing profiles. [3H]strychnine binding to primary cultures increased significantly during the culture period whereas during development in vivo the number of binding sites decreased over time and was hardly detectable in the adult cerebellum. Release of preloaded D-[3H]aspartate evoked by 40 mM K+ from granule cells cultured for seven days was inhibited by glycine by about 50%. Beginning after seven days in culture the ability of glycine to inhibit transmitter release declined to no inhibition after 17 days in culture. Experiments with the non-competitive antagonist, picrotoxinin, showed no blocking effect of 150 microM picrotoxinin on the glycine-induced inhibition of transmitter release. This contrasted with the inhibitory effect of 100 microM picrotoxinin in whole-cell patch-clamp recordings on responses to 500 microM glycine (56% block). Furthermore, it was demonstrated that the amplitude of the glycine activated peak current had the same size after six to seven days and after 16-17 days in culture. Northern blot analysis, and co-injection of messenger RNA plus antisense oligonucleotides into Xenopus oocytes revealed glycine receptor alpha2 and beta messenger RNAs in the cultured granule cells. These findings suggest that granule cells in culture express glycine receptor isoforms containing alpha2 picrotoxinin-sensitive and alpha2/beta picrotoxinin-insensitive receptors.     

Science,technology and development indicators for third world countries—Possibilities for analysis and grouping

The purpose of this article is to make a distinction between (a) a society's ability to generate a scientific and technological potential (generativity), (b) the potential itself and (c) the country's capacity to absorb or receive scientific and technological research results (respectivity). These three complexes are represented by joint indicators covering both levels and structures. A comparison of 30 developing countries (DC) shows, inter alia, that: (a) the polarisation in economic development of the countries considered confirms the view that the future of national development is linked to the scientific and technological potential, (b) joint indicators can interpret better than a comparison of pairs of single indicators, (c) countries with comparable levels of the three capacities (generativity, R & D potential and receptivity) differ mostly in the structures. These structures seem to determine the differences in the use of the capacities, (d) the level of R & D potential is related more closely to the country's ability to absorb scientific and technological results than with its resources for building up this potential.     

Optical,mechanical and water drop impact characteristics of polycrystalline GaP

A polycrystalline form of GaP has been synthesized and its optical and mechanical properties determined. The optical transmission is found to be intrinsic at long wavelengths in the infrared, being limited only by Fresnel reflection and multiphonon absorptions, beginning at approximately 1100 cm^–1. The optical cut-off at short wavelengths is in agreement with earlier measurements on single crystal material. The fracture toughness of the polycrystailine material is found to be greater than that previously reported for single-crystal material. The single impact water drop damage velocity threshold (2 mm drop diameter) was estimated to be 250–280 ms^–1, which is consistent with the measured polycrystalline fracture toughness.